9.If one person's consumption of a good does not preclude another's consumption, the good is said to be:

A. nonrival in consumption.

B. rival in consumption.

C. nonexcludable.

D. excludable.

13.Suppose that Mick and Cher are the only two members of society and are willing to pay $20 and $17, respectively, for the third unit of a public good. Also, assume that the marginal cost of the third unit is $35. We can conclude that:

A. the third unit should not be produced.

B. the third unit should be produced.

C. zero units should be produced.

D. 4 units should be produced.